If three coins are tossed at the same time, what is the probability of getting two tails and one head? Express your answer as a common fraction.
Solution: The probability of getting two tails followed by one head is $\left(\frac{1}{2}\right)^3=\frac{1}{8}$.  The probability of getting a tail followed by a head followed by a tail is also $\left(\frac{1}{2}\right)^3=\frac{1}{8}$.  Finally, the probability of getting a head followed by two tails is $\left(\frac{1}{2}\right)^3=\frac{1}{8}$ as well.  In total, the probability of getting two tails and one head is $\frac{1}{8}+\frac{1}{8}+\frac{1}{8}=\boxed{\frac{3}{8}}$.